Switch



March 15, 1938. H. c. BOOTHROYD SWITCH Filed July 1. 1935 ATTORNEY.

Patented Mar. 15, 1938 UNITED STATES PATENT OFFICE 5 Claims.

My invention relates to an electric switch known as a time-release switch designed primarily for household use in an electric lighting circuit, but equally as well adapted for garages detached from the house, or out buildings such as on farms, and is intended to operate either in the manner of the ordinary push button or toggle type of switch to immediately make or break the circuit in which it is located, or to automatically break the circuit after an interval of time which must elapse between the manual operating of the switch and the actual breaking of the circuit in which the switch is placed.

It is frequently desirable to locate a wall switch at some point in a large room, corridor or hallway, at a point more or less remote from the point of entrance or exit; or it may be desirable to enter one of two inter-connected rooms by one door and later leave by another. In such cases, with the ordinary type of switch one has to proceed in the dark to the point of exit after the lights have been extinguished. This is not only difficult and inconvenient, but at times, may actually be dangerous as, for example, in walkin from ones garage at the end of the yard to ones house late at night in a poorly lighted district.

Therefore, the primary object of the present invention is to provide a switch, interchangeable with the present type, which may be actuated in the manner of the ordinary switch to either immediately close or open the circuit, or which, if the circuit be closed, can be actuated to break the circuit but will doso only alter a period of time,

thereby enabling the person actuating the same to reach the exit before the lights are extinguished.

Another object of the invention is to provide a means by which the time interval during which the circuit will remain closed after the manual operation of the switch can be readily varied from a few seconds to approximately five minutes, after which the circuit is broken automatically.

A fuither object of this invention is to provide that the switch mechanism which causes the instantaneous make and break shall be a complete unit within itself, and independent in its action of the timing mechanism, so that. if for any reason this mechanism were to fail, the switch. could still be operated in the manner of an ordinary switch.

A still further object of this invention is to provide a switch mechanism that with either instantaneous or delayed action will produce a" rapid make and break to prevent arcing.

In the accompanying drawing:

Figure 1 is a plan view of a switch embodying my invention.

Figure 2 is a sectional elevation with the parts in the position in which the lighting circuit is closed but adapted to be automatically opened after a predetermined interval.

Figure 3 is a view similar to Figure 2; the parts being in the position in which the circuit is broken.

Figure 4 is a detail section of the piston and hollow piston rod.

Figure 5 is a detail section illustrating an alternative construction.

The sections of Figures 2 and 3 are taken substantially on the line 22 Figure 1.

2-2 is the switch casing. It has attached to it terminal lb, brush lc, contact 44, and terminal 4e. 3 is a pivoted lever having the oppositely extending arms in and 3b, and an arm 30 extending downwardly and at right angles to said arms. 4 is a framework pivoted at its upper edge, and carrying at right angles the switch blade la which is completely insulated from the frame 4, but at all times in contact with brush is. When the frame 4 is in the position shown in Figure 2, the lighting circuit is complete, the current flowing through terminal 4b and brush 4c, switch blade to to contact 411 and terminal 8e, and when in the position of Figure 3, it is broken, switch blade 40 now being separated from contact 4d. 5 is a compression spring, it upper end carried by the lower end of the arm 3c, and its lower end acting upon the lower portion of the frame 4. The oscillation of the lever 3 carries the upper end of the spring 5 from one side to the other of the pivot axis of the frame 4, and forces said frame to one extreme or the other of its oscillation thus closing and opening the switch by the action of switch blade la making and breaking contact at point Id. l3 and H are push buttons adapted to oscillate the lever 3, and may be replaced by a toggle, as shown in Figure 5. 1 is a cylinder in the casing 2 in alignment with switch mechanism and buttons 13 and H, open at its upper end, and closed at its lower, and 8 is a piston closely fitting and reciprocating in said cylinder. 9 is a hollow piston rod opening through the piston 8 at its lower end and closed at its upper end except for a valve port 10. H is a screw-cap in the upper end or the piston rod 5 which carries a valve adapted to regulate the opening through the port l0 through which air enters, and serves as a third push button. I2 is a compression spring coaxial with the cylinder I and piston rod I and acting to force said piston to the upper end of its stroke. II is a very small port or opening through the wall of the cylinder I somewhat below the piston I when the latter is at the upper end of its stroke. I1 is a lever pivoted at "b in a stationary support II attached to plate II which serves as a mounting for the entire switch mechanism. The upper end llo of the lever I1 is forked and extends over a collar Io fitting piston I so as to be engaged by said collar near the upper end of the piston stroke. to turn said lever about its pivot at "b. He is a lug at the lower end of the lever Il adapted to engage the frame I to hold it in the position at which the light circuit is complete as shown in Figure 2.

The lower end of lug He is beveled 'as lid for a purpose that will presently be explained.

II is a light leaf spring, subordinate to spring l2, acting to force the upper end "a of the lever ll downward whenever button II is The operation of the above described apparatus is as follows:

To instantly complete the circuit, the button II ispresseddowninthemannerofthe ordinary switch thereby turning the lever I about its pivot and carrying the upper end of the spring I to the right of the pivotal axis of the frame I. and thereby oscillating said frame to carry its lower edge to the left hand end of its travel and closing the circuit by means of the attached switch blade Ia making contact at point Id.

To instantly break the circuit, tin button II is pressed down in the manner of the ordinary switch, thereby turning the lever I about its pivot in the opposite direction, and carrying the upper end of the spring I to the left of the pivotal axis of the frame I, and thereby owillating said frame to carry its lower edge in the opposite direction, or to the right hand end of its travel, thereby breaking the circuit by the action of the switch blade Ia becoming separated from contact Id.

To adapt the switch to open the circuit automatically after a predetermined interval the piston I is forced to the lower end of its stroke by pressing upon button II. This forces the air within the cylinder to escape past the piston I leaving a partial vacuum within the cylinder, and permits the lever II under the action of spring II to engage the frame I by the lug IIc as shown in the Figure 2. The button II is also pressed down, carrying the upper end of the spring I to the left of the axis of the frame I, as shown in Figure 2, but the frame is now prevented from oscillating with the consequent breaking of the circuit, because of the restraining acidon of lug IIc.

The piston I immediately begins to slowly rise under the influence of the spring II, but is retarded in its movement by the partial vacuum under it, which is being gradually relieved by air entering the valve port II. The rate at which 2,1 1 was fork at the end Ila of the lever I I turning said lever about its pivot llb and disengaging the lug I'Ic from the frame I, thereby permitting the latter to freely swing under the influence of the spring I to the podtion shown in Figure 3, the lighting circuit thereby being instantly broken.

In the event that button II were to be pressed while the lighting circuit was still open, the lever I! would prevent the return of frame I, if button II were subsequently pressed to close the circuit. For this reason, the end of lever I1 is beveled as Ild so that upon being struck by frame I in moving to the left, it will be pushed out of position, thereby permitting frame I to execute its movement. If desired, lever I I could be constructed to purposely restrain said frame, so that the circuit would remain broken for a predetermined interval, after which it would become complete.

From the above description, it will be observed that if button II is depressed, the circuit is immediately closed, while if button II is depressed, it is immediately broken: but if it is desired to break the circuit not immediately, but after an interval of time which can be regulated from a few seconds to several minutes subuquent to the manual operation of the switch, button II is pushed down, immediately followed by pushing button II in which case the circuit will remain complete but will be broken automatically at the expiration of the interval of time for which the apparatus is set.

What I claim is:

i. In an apparatus of the kind described, the combination of a casing, a pivoted lever in said casing having arms extending in opposite directions from its pivot, a button adapted to actuate one of said arms, a button adapted to actuate the other of said arms, a movable switch apparatus,

a spring interposed between said lever and said switch apparatus to actuate the latter, a cylinder in said casing having a piston adapted to reciprocate therein, a piston rod extending through a wall of said casing adjacent to said buttons, a spring adapted to force said piston to the outer end of its travel, a catch adapted to hold said switch in a position at which the circuit is complete said piston being adapted to engage and actuate said catch to release said switch apparatus at the outer end of its travel, and means for retarding the motion of said piston.

2. In an apparatus of the kind described, the combination of a casing, a pivoted lever in said casing having arms extending in opposite directions from its pivot, a button adapted to actuate one of said arms, a button adapted to actuate the other of said arms, a movable switch apparatus. a spring interposed between said lever and said switch apparatus to actuate the latter, a cylinder in said casing having a piston adapted to reciprocate therein, a piston rod extending through a wall of said casing adjacent to said buttons, a spring adapted to force said piston to the outer end of its travel, a spring-pressed pivoted lever adapted to engage said switch apparatus to hold it in the position in which the circuit is complete, said piston being adapted to engage and actuate said spring-pressed lever to release said switch at the outer end of its travel, and means for retarding the motion of said piston.

3. In an apparatus of the kind described, a casing, a pivoted lever in said casing, a button adapted to oscillate said lever about its pivot, a"

movable switch apparatus, a spring interposed between said lever and said switch apparatus to actuate the latter, a cylinder in said casing having a piston adapted to reciprocate therein, a piston rod extending through a wall of said casing adjacent to said button, a spring adapted to force said piston to the outer end 01' its travel, a catch adapted to hold said switch in a position at which the circuit is complete, said piston being adapted to engage and actuate said catch to release said switch apparatus at the outer end of its travel, and means for retarding the motion of said piston.

4. In an apparatus of the kind described, the combination of a casing, a pivoted lever in said casing, a button adapted to oscillate said lever about its pivot, a movable switch apparatus, a spring interposed between said lever and said switch apparatus to actuate the latter,-a cylinder in said casing having a piston adapted to reciprocate therein, a piston rod extending through a wall of said casing adjacent to said button, a spring adapted to force said piston to the outer end of its travel, a pivoted lever adapted to engage said switch apparatus to hold it in the position in which the circuit is complete, said piston being adapted to engage and actuate said lever to re-,.

lease said switch at the outer end of its travel, and means for retarding the motion of said piston. 5. In an apparatus of the kind described the combination of a casing, a switch apparatus in said casing, a spring adapted to actuate said switch apparatus, a button on said casing adapted to act through said spring to actuate said switch apparatus, a cylinder and piston therein in said casing, a spring adapted to actuate said piston to the outer end of its travel, a catch adapted to engage said switch apparatus to prevent its actuation by the first named spring, said piston being adapted to release said catch at the outer end of its travel, means for retarding the automatic motion of said piston, and a button on said casing adjacent to the first named button adapted to be manipulated to force said piston inward and permit the said engagement of said catch.

HAROLD C. BOOTHROYD. 

